People wishing to be contacted by telephone must reveal their telephone numbers and for most situations, this does not represent a problem; e.g. revealing phone numbers to friends and family. However, situations do exist where people wish to be contacted by telephone without revealing their assigned (home or cellular) telephone number. For example, a person placing a classified ad to sell an automobile needs to publish a number that potential buyers can call, but the seller does not want to continue to receive calls after the car is sold.
Within the current fixed and cellular telephone networks, telephone numbers are generally associated with a specific access line or specific terminals. For example, a residential phone number is tied to a specific access line and a cellular phone number is tied to a specific handset. In the fixed telephone network, the linkage between the telephone number and the access line is nearly permanent.
This physical, semi-permanent mapping of telephone numbers to access lines or terminals can be a disadvantage in many situations, including that noted above of a person who places a classified advertisement to sell a car. In particular, the person placing the ad has no way to prevent people from calling after the car has been sold. In addition, the proliferation of computerized telephone directories allows people to determine the geographic address associated with the telephone number, and therefore publication of a standard telephone number reveals a substantial amount of information which the person placing the ad may not want to reveal. While in cellular telephone networks, the association between a telephone number and the handset can be altered, this transition typically entails a time-consuming process, e.g. the customer calls the service provider and transfers service to a new handset.
This is an even greater problem for people trying to use private or semi-private facilities for public purposes. Obviously, people with private numbers do not want to reveal such number in a public forum, such as a classified advertisement. In addition, customer service centers have a related problem. Customer service centers often accept inquiries via e-mail or voice mail, and then make return calls to the customers. If the customer cannot be reached directly, the representative may leave a telephone number for the customer to call back. However, once this number is given to the customer, there is no way to prevent the customer from making direct calls to that number for subsequent requests or unrelated activity.
In another similar situation, doctors who return calls to patients generally will not leave their private numbers in cases where they do not connect, in order to avoid having patients contact them directly. This scenario can be further complicated by the use of certain AIN features. For example, to protect privacy, the doctor may have Caller-ID Block, and to screen incoming calls the patient may have Anonymous Call Reject. This combination will effectively prevent the doctor and patient from communicating.
The semi-permanent linkage of phone number to location is not the case for certain classes of numbers. In particular, toll free numbers such as 800 and 888 numbers are logical numbers that are matched dynamically to addressable numbers in a database within the telephone network. These toll free numbers have other properties that limit their usefulness in certain situations. In particular, these numbers also involve an alternate billing model where the called party pays, and a person placing a classified ad will not generally want to pay for all the calls that come in response. Further, these number have no geographic significance whatsoever and therefore, callers responding to an ad can not use the locational information in the number (area code and exchange) to get an idea of how far they might need to travel to see the item for sale, (for example, to see and test drive a car). Toll-free numbers are not appropriate in these situations.
Therefore, there remains a need in the art for improvements in the field of dynamic telephone numbers.